1. Field of the Invention
This invention relates to exercising devices and particularly to knee bending exercise devices adapted to rehabilitate a knee after surgery.
2. Description of the Prior Art
The prior art includes various publications and patents pertaining to exercise devices but none of the devices are particularly adapted to stretching the muscles controlling the knee and simultaneously bilaterally stabilizing the knee joint to avoid lateral injurious movements subsequent to knee surgery.
In 1974, a martials publication included an advertisement describing a STRETCHER-CIZER apparatus. The STRETCHER-CIZER comprises a leather harness connected to two overhead in line pullers via a rope. The STRETCHER-CIZER is designed as a leg muscle stretcher stretching the leg muscles and the joint at the junction between the leg and the torso.
Another leg stretching machine is illustrated in the May, 1980 issue of Black Belt Magazine. This leg stretcher entitled "G.U.S." is similarly adapted to stretch the hip joint and muscles which control the juncture between the leg and the torso. One illustration shows the device also used to harness both ankles to assist in sit ups.
U.S. Pat. No. 3,638,939 to Langley further discloses a simple bar-like device which includes rollers at each end hereof and an intermediate handle. The device is positioned between one's legs and pulled towards the abdomen forcing the legs further and further apart and stretching the muscles associated therewith in the same manner as the G.U.S. machine.
U.S. Pat. No. 3,834,694 to Pridgen relates to an apparatus also utilized pulleys wherein one leg is strapped to a mattress an the other leg is coupled to weights via overhead pulley system. A rope is also coupled to the weights through a one way clutch. The same patent further discloses a post which is gripped while the one moves his or her legs back and forth against spring bars mounted to the post. Also in the same general area are U.S. Pat. No. 4,046,373 to Kim which discloses a multi-purpose frame for stretching one's legs and U.S. Pat. No. 4,111,415 to Reitano which discloses utilizing hand grips and foot grips to develop particular muscles for karate.
Black Belt magazine in its February, 1982 issue discloses another leg stretching machine called the "Hurley Stretch Rack" which again is a means improvised to provide stretching of the hip joint, particularly, the junction between the leg and the torso.
U.S. Pat. No. 4,132,404 to Wilson discloses a leg stretching apparatus comprising two movable platforms having ball casters with free movement in opposite directions, the platforms being joined by an appropriate coupling means. U.S. Pat. No. 4,139,193 to Felber et al further discloses a kick training aid for karate comprising an adjustable pole with a foot piece on the top thereof mounted for the universal movement on a base. The pole is extended to accommodate individuals of different heights. And, U.S. Pat. No. 4,277,062 to Lawrence discloses a leg stretching exercise device comprising a platform attached to a bar with pulleys attached to each end.
In 1984 U.S. Pat. No. 4,445,684 was issued to Ruff for a leg stretching device which includes a set fixed to a shaft having a winch connected to a slidably mounted spreader. In 1991 U.S. Pat. No. 4,988,096 was issued to Jones for a muscle stretching apparatus for stretching an individual's legs which utilizes a plurality of rings secured to an individual flexible lien with a weighted member secured at the other end thereof. Also, in 1991 U.S. Pat. No. 5,067,709 was issued to Christensen for a device for stretching and strengthening the muscles of the lower back and legs of a person in a supine position.
Another leg stretching machine to develop and assist a person performing the Chinese split was issued as U.S. Pat. No. 5,147,266 to Ricard in 1992. FIG. 3 of Ricard shows a winch connected to two independent left and right ropes with the purpose of bilateral stretching of the hip joints and the area wherein each leg adjoins the torso.
In 1992 U.S. Pat. No. 5,122,106 was issued to Atwood et al for a stretching device for stretching the muscles, tendons and joint capsules of the hip, thigh, calf, and foot by completely cradling the foot and allowing the leg to be swung upward from a supine position.
It has been determined in recent year that after knee surgery regular physical therapy enhances recovery and shortens the time for recovery, especially for surgery involving repair of torn ligaments in the knee. With the advent of greater emphasis on physical fitness and exercise and with more and more participation by older individuals in sports there has been a dramatic rise in ligamentous injuries involving the knee. After surgery and after an initial period of healing regular stretching of the muscles of the knee increases both the flexibility and range of motion of the muscles involved.
To avoid overtaxing and injury to the knee muscles after surgery gradual static exercise and gradual knee bending stretches are recommended to be used rather than dynamic stretches. In performing knee bending exercise it has been found to be difficult for either the exerciser or an assistant to apply a sturdy, safe load on the leg. Moreover, it is not possible to accurately apply the same directional purely rearward force against the leg and knee joint each tie the knee related muscles are to be stretched, thus the extent to which the knee related muscles are stretched non-laterally can vary considerably from day to day and time to time using exercise without and assisting apparatus to restrict lateral movement.
It is known that after a muscle is stretched to or near its maximum level for a period of time if maximum contraction of the muscle is made and the muscle has been allowed to relax, a proprioceptive neuromuscular facilitation phenomenon occurs whereby a dip in the muscle stretch reflex occurs so that the muscle can be stretched somewhat further.
It is desirable to flex the muscle so the knee joint while lying in a prone position. Moreover, it is desirable to bend at the knee by bending the leg strictly backwards and then strictly forward through a qualifiable range of motion which can be repeated to apply the same amount of rotation and force.
In another apparatus, a motorized swing arm is strapped to the lower leg or lower arm to move the distal section of the limb through a range of motion about the knee or elbow joint, thereby to provide physical therapy to increase the range of motion in a knee joint that has reduced mobility. An example of this related prior art type device is disclosed in U.S. Pat. No. 4,089,330. However, one drawback of this particular type of device is that it is large, cumbersome, and too expensive for individuals to purchase for home use. Moreover, this type of device also places a constant load on the body limb rather than simply holding the leg in a moderate bent position and allowing the leg to be straightened and relieved if necessary, thereby removing the possibility and fear of overstretching while in this position and thus not allowing the user to relax.